A body weighing 50 N is placed on a wooden table. How much force is required to set it into motion? Coefficient of friction between the table and the body is 0.3.​

If the coefficient of static friction is 0.3, then the minimum force required to get it moving is equal in magnitude to the maximum static friction that can hold the body in place.

By Newton's second law,

• the net vertical force is 0, since the body doesn't move up or down, and in particular

∑ F = n - mg = n - 50 N = 0   ==>   n = 50 N

where n is the magnitude of the normal force; and

• the net horizontal force is also 0, since static friction keeps the body from moving, with

∑ F = F' - f = F' - µn = F' - 0.3 (50 N) = 0   ==>   F' = 15 N

where F' is the magnitude of the applied force, f is the magnitude of static friction, and µ is the friction coefficient.

nec chapter 5 contains

c. information on special occupancy areas

nec chapter 6 covers

a. special equipment

which of the following rules contain the words shall or shall not and must be adhered to?

b. mandatory rules

which of the following rules identify actions that are allowed but not required and typically cover options or alternative methods?

c. optional rules

which of the following serves as the introduction to the nec and provides an overview of the book?

a. nec article 90

organizations that test products for safety are

c. nrtls

the nec is published by the

a national fire protection association

the nec is divided into

b. 9 chapters

the nec provides informative annexes for

c. informational materials and examples

two terms from nec article 100 that trainees should become familiar with are

b. labeled and listed

explanation: